基于PEMS的缸内直喷汽油机颗粒物排放特性

摘要

Gasoline particle filter (GPF) is one of the most effective potential particulate emission limit technology for a direct injection gasoline (GDI) engine along with the increasingly stringent national regulations version 6 about emissions. This paper investigated the effect of speed and load variation on the emission characteristics of engine particle number (PN) and the effect of GPF capture efficiency under different temperatures using a test equipment of portable emission measurement system (PEMS) in a 2.0T GDI engine equipped with a GPF. The results showed that the total particle number (PN) concentration of GDI gasoline engine has a trend of "U", which increases sharply after the increase of load, and the PN concentration in the GPF is higher than that before the GPF. The accumulation of ash layer increases the interception and deposition of the mechanism of the particulate filter of the gasoline engine, deep bed filtration regime enhances and the filtering efficiency increases.%为适应国6等日益严苛的排放法规,汽油机颗粒捕集器(GPF)被认为是一种应对缸内直喷(GDI)汽油机颗粒物排放限值最有效的潜在技术.本文以装有GPF的2.0T GDI发动机为研究对象,采用便携式排放测试系统(PEMS)研究了转速、负荷变化对发动机颗粒数(PN)排放特性的影响,以及不同排温下GPF的捕集效率的影响.结果表明:GDI汽油机总颗粒物数量浓度在转速不变时,随着负荷的增加呈现明显的先下降后急剧上升的U型趋势;GPF再生过程中,会出现GPF后的PN浓度大于GPF前的浓度的现象;一定程度内,灰分层的积累使汽油机颗粒捕集器过滤机理中的拦截沉积作用增强,深层过滤效果明显,捕集效率快速增大.